Tire pressure alarm



y 1, A. M. HEATH TIRE PRESSURE ALARM Filed May 21, 1942 2 Sheets-Sheet l Inventor flriur M Heal h y 1, 1945- A. M. HEATH 2,374,748

. TIRE PRESSURE ALARM' Filed May 21, 1942 I 2 Sheets-Sheet 2 Inventor J f irzkwi' flg. Hem? y ,/I 5' 211107718 f Patented May 1, 1945 l ArtnurM-Heam, Houston, Tex.

, ApplicationiMay 21, [1942, SerialNo. 443,976 [,1

2 Claiin'sr' (c1. ire-30 The present invention relates to new, and useful improvements in tire pressure alarms, particularly for motor vehicles, and has for its primary object to provide, in a manner as hereinafter set forth, a device of this character comprising novel means for signalling when the tire is either over-inflated or under-inflated.

Other objects of the invention are to provide a tire pressure alarm of the aforementioned character which will be comparatively simple in construction, strong, durable, highly eflicient and reliable in use, compact, and which may be manufactured at low cost.

All of the foregoing and still further objects and advantages of the invention will become apparent from a study of the following specification, taken in connection with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views, and wherein:

Figure l is a view in side elevation, showing a tire pressure alarm constructed in accordance with the present inventionmounted on a vehicle wheel. 7

Figure 2 is a view in side elevation of the hub cap with a portion thereof broken out, showing the air pressure chamber in vertical section.

Figure 3 is a view. in vertical section through the device.

Figure 4 is a fragmentary view in vertical section through the lower portion of the pressure chamber.

Figure 5 is a view in vertical section through one of the air actuated motors. V

Figure 6 is a fragmentary view in horizontal section, showing one of the clappers striking the hub cap.

Referring now to the drawings in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a hub cap I for a vehicle wheel 2. A pneumatic tire on the wheel 2 is indicated at 3. A removable plate 4 permits access to be had to the interior of the hub cap I. An air pressure chamber 5 is mounted in the upper portion of the hub cap I. A removable closure 6 permits access to be had to the interior of the pressure chamber 5. A conduit I, including a flexible section, connects the pressure chamher 5 to the usual valve stem of the tire 3.

A horizontal pipe 8 in the hubcap I is connected at an intermediate point, as at 9, tothe pressure chamber 5. Air actuated motors I0 are mounted on the ends of the pipe 8. In the embodiment shown, the motors Ill include circular casings II which communicate with the pipe ii. Journaled in the casing s I I are shafts I2 Q having vanes I3 fixed thereon. Clappers I4 are fixed on one end portion of the shafts I2, said clappers being engagealble withthe hub cap I when the motors III are actuated.

Tubes I5 extend upwardly in the chamber 5 from the bottom I6 thereof. Casings H are provided on the upper ends of the tubes I5. The casings I1 are open at their tops and mounted therein are diaphragms I8. Coil springs I9 bias the diaphragms I8 in one direction.

Rotary valves 20 are interposed in the pipe 8 between the connection 9 and the rotors I0. Ver

tically adjustable rods 2| connect the diaphragms I8'to the arms 22 of the valves 20;

It is thought that the operation of the device will be readily apparent from aconsideration of the foregoing. Briefly, the air pressure in the chamberli is the same as in the pneumatic tire 3. The valves 20 are normally closed. Should the pressure in the tire be too great, one of the diaphragms I8 will overcome the tension of its respective coil spring I9, which is comparatively light or weak, for opening the respective valve 20, thus permitting the air from the pressure chamber 5 to actuate the motor In on one end of the pipe 8. When the motor is thus actuated the clapper I4 thereon strikes the hulb cap I for warning the operator of the vehicle that the pressure in the tire is too high. When the air in the tire drops to the correct pressure, the valve is again closed by its respective diaphragm I8 which is now actuated by its respective coil spring I9. If the pressure in the tire. is too low the other diaphragm I8 is forced outwardly by its respective coil spring I9. Thus, the other valve 20 is opened for actuating the motor) on the other other motor to strike the hub cap I. 'As this other diaphragm I8 is moved outwardly by its coil spring I9, the respective valve 20 continues to turn for shutting off the air to prevent deflation of the tire.

It is believed that the many advantages of a tire pressure alarm constructed in accordance with the present invention will be readily understood, and although a preferred embodiment of the device is as illustrated and described, it is to be understood that changes in the details of construction and in the combination and arrangement of parts may be resorted to which will fall within the scope of the invention as claimed.

What isclaimed is:

1. A tire pressure alarm comprising a hub cap for mounting on a vehicle wheel, a pressure,

chamber within said hub cap, means connecting said pressure chamber to a pneumatic tire on the wheel for receiving air under pressure therefrom, an air actuated motor connected to the chamber for receiving air therefrom for actuation thereby, a clapper actuated by saidmotor and engageable with the hub cap, and means for controlling the fiow'of air to said motor, the last-namedmeansincluding a control valve interposed in. the conriection between the motor and the pressure chamber, a diaphragm mounted in the chamber and controlled by the pres-;

sure therein, a spring acting against said diaphragm and a rod. connecting the valve'to said diaphragm for actuation thereby.

2. A tire pressure alarm of the character dea scribed comprising a hub cap 'fo'rmounting on 2,374,74s iii-93" I on a, pneumatic tire on the wheel for receiving air under pressure'therefrom, a branched pipe connected, at one end, to the chamber, air, actuto the motors, casings mounted in the chamber,

diaphragms mounted insaid casings and subjected to-the pressure in the ;cham ber,; springs act-- ing against said diaphrag'msand rods iconnecting the valves to said diaphragms for actuation thereby, one valve'being arranged to be opened by pressure on one diaphragm when said pres sure rises above a predetermined degree, the

,other vaivebeing arranged to be opened by one of said springs when the pressure lowers below I said de'gree'andto be closed thereby as the presa vehicle wheel, a pressure chamber within said f hub cap, a conduit connecting said chamber to sure lowers further.

' ARTHUR M; HEATH. 

